Index: head/sys/dev/e1000/if_em.c
===================================================================
--- head/sys/dev/e1000/if_em.c
+++ head/sys/dev/e1000/if_em.c
@@ -3735,29 +3735,38 @@
  		offload |= CSUM_TCP;
  		tucss = hdr_len;
  		tucso = hdr_len + offsetof(struct tcphdr, th_sum);
- 		/*
- 		 * Setting up new checksum offload context for every frames
- 		 * takes a lot of processing time for hardware. This also
- 		 * reduces performance a lot for small sized frames so avoid
- 		 * it if driver can use previously configured checksum
- 		 * offload context.
- 		 */
- 		if (txr->last_hw_offload == offload) {
- 			if (offload & CSUM_IP) {
- 				if (txr->last_hw_ipcss == ipcss &&
- 				    txr->last_hw_ipcso == ipcso &&
- 				    txr->last_hw_tucss == tucss &&
- 				    txr->last_hw_tucso == tucso)
- 					return;
- 			} else {
- 				if (txr->last_hw_tucss == tucss &&
- 				    txr->last_hw_tucso == tucso)
- 					return;
- 			}
-  		}
- 		txr->last_hw_offload = offload;
- 		txr->last_hw_tucss = tucss;
- 		txr->last_hw_tucso = tucso;
+		/*
+		 * The 82574L can only remember the *last* context used
+		 * regardless of queue that it was use for.  We cannot reuse
+		 * contexts on this hardware platform and must generate a new
+		 * context every time.  82574L hardware spec, section 7.2.6,
+		 * second note.
+		 */
+		if (adapter->num_queues < 2) {
+ 			/*
+ 		 	* Setting up new checksum offload context for every
+			* frames takes a lot of processing time for hardware.
+			* This also reduces performance a lot for small sized
+			* frames so avoid it if driver can use previously
+			* configured checksum offload context.
+ 		 	*/
+ 			if (txr->last_hw_offload == offload) {
+ 				if (offload & CSUM_IP) {
+ 					if (txr->last_hw_ipcss == ipcss &&
+ 				    	txr->last_hw_ipcso == ipcso &&
+ 				    	txr->last_hw_tucss == tucss &&
+ 				    	txr->last_hw_tucso == tucso)
+ 						return;
+ 				} else {
+ 					if (txr->last_hw_tucss == tucss &&
+ 				    	txr->last_hw_tucso == tucso)
+ 						return;
+ 				}
+  			}
+ 			txr->last_hw_offload = offload;
+ 			txr->last_hw_tucss = tucss;
+ 			txr->last_hw_tucso = tucso;
+		}
  		/*
  		 * Start offset for payload checksum calculation.
  		 * End offset for payload checksum calculation.
@@ -3773,29 +3782,38 @@
  		*txd_upper |= E1000_TXD_POPTS_TXSM << 8;
  		tucss = hdr_len;
  		tucso = hdr_len + offsetof(struct udphdr, uh_sum);
- 		/*
- 		 * Setting up new checksum offload context for every frames
- 		 * takes a lot of processing time for hardware. This also
- 		 * reduces performance a lot for small sized frames so avoid
- 		 * it if driver can use previously configured checksum
- 		 * offload context.
- 		 */
- 		if (txr->last_hw_offload == offload) {
- 			if (offload & CSUM_IP) {
- 				if (txr->last_hw_ipcss == ipcss &&
- 				    txr->last_hw_ipcso == ipcso &&
- 				    txr->last_hw_tucss == tucss &&
- 				    txr->last_hw_tucso == tucso)
- 					return;
- 			} else {
- 				if (txr->last_hw_tucss == tucss &&
- 				    txr->last_hw_tucso == tucso)
- 					return;
+		/*
+		 * The 82574L can only remember the *last* context used
+		 * regardless of queue that it was use for.  We cannot reuse
+		 * contexts on this hardware platform and must generate a new
+		 * context every time.  82574L hardware spec, section 7.2.6,
+		 * second note.
+		 */
+		if (adapter->num_queues < 2) {
+ 			/*
+ 		 	* Setting up new checksum offload context for every
+			* frames takes a lot of processing time for hardware.
+			* This also reduces performance a lot for small sized
+			* frames so avoid it if driver can use previously
+			* configured checksum offload context.
+ 		 	*/
+ 			if (txr->last_hw_offload == offload) {
+ 				if (offload & CSUM_IP) {
+ 					if (txr->last_hw_ipcss == ipcss &&
+ 				    	txr->last_hw_ipcso == ipcso &&
+ 				    	txr->last_hw_tucss == tucss &&
+ 				    	txr->last_hw_tucso == tucso)
+ 						return;
+ 				} else {
+ 					if (txr->last_hw_tucss == tucss &&
+ 				    	txr->last_hw_tucso == tucso)
+ 						return;
+ 				}
  			}
- 		}
- 		txr->last_hw_offload = offload;
- 		txr->last_hw_tucss = tucss;
- 		txr->last_hw_tucso = tucso;
+ 			txr->last_hw_offload = offload;
+ 			txr->last_hw_tucss = tucss;
+ 			txr->last_hw_tucso = tucso;
+		}
  		/*
  		 * Start offset for header checksum calculation.
  		 * End offset for header checksum calculation.